The aim of our OTKA project was to clone and characterize 2P-type and voltage dependent potassium channels. We have focused mainly on their regulation and physiological role. We published the second paper about the cloning of the 2P type TRESK channel and we described its calcium dependent regulation. We have shown that TRESK, unlike any other 2P-type potassium channel, is activated by elevation of the cytoplasmic Ca2+ concentration. This effect is mediated by the calcium dependent phosphatase, calcineurin. Calcineurin dephosphorylates phosphoserine 276 in the intracellular loop of TRESK what results in its increased conductance of almost 10-fold. We recognized an amino acid stretch in the intracellular loop of TRESK (PQIVID) which is similar to a motif possessed by the most important substrate of calcineurin, NFAT. We have shown that calcineurin, when activated by Ca2+, attaches to TRESK through this motif and this binding is necessary for the dephosphorylation/activation of the channel. We also analyzed the pharmacological properties of TRESK; based on these results TRESK current can be distinguished from that of other 2P potassium channels. In addition, the degree of the activation of TRESK can also be estimated.
After we had cloned the Kv8.2 voltage sensitive potassium channel we showed that the subunit is expressed predominantly in the photoreceptors of the retina and its current significantly contributes to the unique electrophysiological properties of these cells.

Czirják G, Enyedi P.: Targeting of calcineurin to an NFAT-like docking site is required for the calcium-dependent activation of the background K+ channel, TRESK., J Biol Chem. 2006 May 26;281(21):14677-82., 2006